Answer:
a) A. Because the population diameter of Ping-Pong balls is approximately normally distributed, the sampling distribution of samples of 4 will also be approximately normal.
b)
And using a calculator, excel or the normal standard table we have that:
c)
And using a calculator, excel or the normal standard table we have that:
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problem
Part a
Let X the random variable that represent the diameter of a brand of ping pong of a population, and for this case we know the distribution for X is given by:
Where and
And we select a sample of size n =4 and we want to find the distribution for
Since the distribution for X is normal then the distribution for the sample mean is normal and given by:
So the best option for this case would be:
A. Because the population diameter of Ping-Pong balls is approximately normally distributed, the sampling distribution of samples of 4 will also be approximately normal.
Part b
We can use the z score given by:
And using a calculator, excel or the normal standard table we have that:
Part c
And using a calculator, excel or the normal standard table we have that: